Ore concentration.



treatment of such an ore.

ORE CONCENTRATION.

No Drawing.- Application-filed September 30, 1914, Serial No. 864,320. Renewed June 20, 1917. Serial No.

Specification of Letters Patent.

Patented July 2%, 1917.

To all whom it may concern.

Be it known that I, Gnoncn ALBERT CHAP- MAN, a subject of the King of England, residing at Anaconda, Deerlodg'e county, State of Montana, United States of America, have invented certain new and useful Improvements in Ore Concentration, of which the following is a specification.

This invention is for improvements in or relating to ore concentration and has 'particular reference to the concentration of ores by flotation, for example by the well-known agitation froth process.

As is well-known the formation of a min eral bearing froth in that process is assisted by the fine pulverization of the ore, or by the presence in the ore pulp of a certain proportion of slime mineral. of certain ores, however, a part of the slimes (both mineral and gangue, or either) is in a colloidal or quasi-coll0idal state; and it is found that the presence of colloidal slimes in the pulp, if in excess of that which may be usefully employed in assisting in the formation of good stable froths, is a serious impediment to the successful concentration of the sulfid values in such an ore. In some instances this interference has been to some extent overcome by the dilution of the pulp so as to diminish the proportion of solids in suspension. in other cases the processes as described in the previous United States Patents No. 1,102,873 to myself and Tucker and No..1,102,874 to myself, both issued July 7, 1914, have been successfully applied to ores of this type. In some cases where the proportion of colloids has been very high it has been hitherto difficult or impossible to efiect commercial or profitable separation by the flotation The actual cause of failure has not been scientifically explained in detail. Apparently the tendency is for the colloid matter in sus ension to adsorb or otherwise render ine ective the frothing agents which are used.

An attempt has been made to employ in admixture with the pulp certain coagulable materials with the object of bringing about a settlement of the suspended matter but it is found that during coagulation and settlement the sulfid mineral particles are collected in the coagulations and cannot thereafter be separated by flotation.

stances containing In the case the An essential feature of this invention consists in adding to the pulp certain subacid radicals of oxyacids of the aliphatic group which enable an ore pulp containing a large proportion of colloidal particles to be successfully treated by fiotati0n. As these substances have been.

them colloid agents.

The colloid agents which have been found most effective are tartaric acid or citric acid or salts of these such as argol, em ployed in solution in the pulp.

In practice the pulp of powdered ore and water is prepared as usual and a very small proportion of the colloid agent, 'such as tartaric acid or argol is added thereto, before or during the agitation and aeration.

hlS invention may advantageously be used in conjunction with the processes described in the previous United States Patents Nos. 1,102,873 and 1,102,874, above referred to, that is to 'say, the water to be used in the froth flotation process may be agitated with a modifying agent such as cresol or the like and with the colloid agent, efore coming into contact with the ore to be treated: or the ore may be ground with water containing the colloid agent or containing both the colloid agent and a modifying agent such as cresol.

he following is a description of one example of the use of this invention: The ore of the Burro Mountain Company of New Mexico, United States of America (a porphyry ore) whencrushed gives a large proportion ofinterfering colloids and the method of treating the ore according to this invention corresponds very closely with that described with reference to the drawings in the aforesaid United States Patent No. 1,102,874 and during the final grinding in Hardinge mill there is added to the pulp a small proportion (say from of a pound per ton of ore) of argol-in additi0I(1il to the modifying agent or oil already use Again, the ore of th Anaconda Copper Mine in Montana, United States of America when crushed produces slimes which mainly pass through a 200 mesh screen and a large proportion of the slime is in a colloidal state. The ore has been experimentimproved aforesaid United States Patent No. 1,102,874:

and it is found that by agitating the modifying agents or frothing agents with a warm solution of ar 01 and then adding the mixtime to a flotation circuitthe result is greatly According to this-invention the employ ment of a colloid agent such as tartaric acid or argol in solution in the water or in the pulp may be combined with any of the known flotation processes.

Where sulfuric acid is employed in the flotation process, the colloid agent may be introduced at an earlier stage than the s'ulfuric acid. For example the colloid agent may be used at the final grinding stage in the preparation of the pulp, or the colloid agent may be added to the pulp before the flotation process begins, or the colloid agent and a modifying mixed or agitated with the pulp before the sulfuric acid is added. On the other hand the colloid agents of the type described can be effectively employed in cases where sulfuric acid is not used.

Again, colloid agents of the type described may be used in theflotation process with or without the'employment of 011 and with or without the employment of any other, added agent.

What I claim as my invention and desire to secure by Letters Patent is 1. A process for concentrating ores which consists in mixing a powdered ore with Water containing in solution a substance containing an acid radical of an oxyacid of the aliphatic group, quantity of a mineral-frothing agent, agitating the mixture to form a froth and separating the froth.

2. A process for concentrating ores which stituents from an ore or frothing agent may be.

containing also a small asagna consists in mixing a powdered ore with water containing in solution argol, and containing also a small quantity of a mineralfrothing agent, agitating the mixture to 1 form a froth and separating the froth.

3. A process for separating certain con loidal slimes which consist in dissolvlng n the pulp of such an ore a an acid radical of an oxyacid of the aliphatic group, adding to the pulp a small quantity of a mineral-frothing agent, agitating the mixture to form a froth, and separatiug the froth.

4. A process for separating certain constituents from an ore pulp argol in the pulp of such an ore, adding to the pulpv a small quantity of a mineral frothing agent, agitating the mixture to form a froth, and separating the froth.

- 5. A process for concentrating ores which consists in grinding the ore with water containing in solution a substance containing an name to this specification in the presence of two subscribing wltnesses.

enonen ALBERT CHAPMAN; Witnesses:

- -HENRY D. WILLIAMS,

HARRY C. Lnwrs.

substance containcontaining colloidal slimes which consists in dissolving and then agitatand separating pulp containing col- 7 

